ISO 15189 Laboratory Accreditation Standard Requirements

Standard for Particular Requirements for Quality and Competence

The ISO 15189 laboratory accreditation standard requirements matter because as methods become standardized globally, documenting them, running them consistently, transferring knowledge, ensuring traceability, and enabling comparison all become important. For these reasons, accreditation work for testing, medical, and calibration laboratories has grown in importance. Starting in 1989, accreditation certification for testing and calibration laboratories was based on EN 45001, and since December 1999 it has been based on ISO/IEC 17025, which was drafted using experience from the earlier standard and ISO/IEC Guide 25. Medical laboratories, with their particular patient and clinical-staff requirements and expectations, set their accreditation requirements based on ISO 15189, the Medical Laboratories: Particular Requirements for Quality and Competence standard, which was built on ISO/IEC 17025 and ISO 9001.

The ISO 15189 laboratory accreditation standard is understood to have its own specific regulations and requirements applicable to all or part of the professional staff, to their productivity, and to their responsibilities within the scope. ISO 15189 is a standard built on top of ISO 17025, and while ISO 17025 only defines laboratory competence within a quality-management framework, ISO 15189 specifically addresses the medical laboratory function. Medical laboratory services cover, in addition to safety- and ethics-related analyses, the organization of requests, patient preparation and information, sample collection, storage, transport, processing and analysis of clinical samples, validation, interpretation, and reporting.

Medical laboratories sit at the center of information flow across every healthcare setting. Clinical staff base their routine diagnoses and treatments on the results of these analyses, where clinical judgment depends heavily on laboratory output. In ideal conditions, every practice should have a network that ensures test results are consistent, reliable, and accurate worldwide, regardless of location, and that monitors those qualities. Medical laboratories holding high professional and technical standards, and the quality of the service they produce, matter directly to both the public and patients. For that reason, medical laboratories, like other organizations, focus on continuous improvement practices. Unlike other organizations, patient safety and confidentiality sit at the forefront for medical laboratories. Medical laboratories work to prove their competence within their service scope by anchoring on ISO 15189, the most suitable standard for analysis and assessment activity, and by communicating their standing to the public as aligned with the relevant standard.

Accreditation of medical laboratories covers the administrative and technical analysis of a laboratory's capacity to deliver quality service by independent external auditors, the confirmation of that capacity, and periodic review for continuous improvement.

Three major bodies are active in medical laboratory accreditation globally: the International Organization for Standardization (ISO), the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), and the College of American Pathologists (CAP). Laboratory accreditation in Turkiye began operating in 2001, and since 2008 mutual recognition agreements have been signed with the European Accreditation Cooperation (EA). The EA is a full member of the International Laboratory Accreditation Cooperation (ILAC) and the International Accreditation Forum (IAF).

The core task of a medical laboratory in the accreditation process is to establish its technical competence correctly at each stage: pre-examination, examination, and post-examination. Studies on medical laboratories have found that a large share of results inconsistent with patients' clinical status originate from deficiencies in the pre-examination stage. To minimize the risk of errors arising at this stage, patient preparation before sample collection must be done correctly, samples must be taken under appropriate conditions and stored properly, and the critical transport step must take place under the right conditions. Within the quality-assurance framework and accreditation scope, temperature control and tracking of transport containers can be maintained with data loggers. After all these steps, the sample's entry into the laboratory must also be registered under confidentiality and reliability principles. Barcoding and information systems used for this purpose prevent any confusion or information loss in the records.

The most important analytical phase is the examination itself. Through the systems used during sample registration, the area in which the requested tests will be run is automatically recorded, and samples are classified by working area. At this stage, internal quality control, a non-negotiable requirement of accreditation, is run and recorded daily. This approach surfaces any nonconformities in analysis performance, day-to-day variation, or traceability. When a nonconforming result occurs, examination is halted until the nonconformity is resolved. After the needed adjustments are made and the obstacles are removed, patient-sample examination can resume. External quality control is also a non-negotiable part of the accreditation process. It is run on a regular cycle, with wide participation, through proficiency-testing providers such as KBUDEK, INSTAND, RfB-DGKL, MLE, and UKNEQAS. For tests where no external quality-analysis program is available, or where the situation calls for it, inter-laboratory comparison (ILC) testing can be used to perform a conformity review. All of this quality assessment work secures examination results and provides ongoing method-quality assurance through continuous method monitoring.

Accreditation is entirely voluntary. Its foundations are impartiality, competence, and independence. Beyond raising service quality, reducing costs, and verifying reliability, accreditation provides credibility and acceptance at international platforms. Third-party recognition means the laboratory only needs one assessment, avoiding the need for multiple reviews. Continuous training and development of laboratory staff builds a competent, professional team in the sector. Tracking evolving technology, refreshing equipment, and advancing existing methods together bring laboratories to professional maturity, enabling them to participate effectively in their fields. The result is higher patient and family trust and satisfaction, positive capacity effects, and increased standing.

Successful quality-improvement programs in medical laboratories can be sustained by establishing ongoing organizations that track reports, care-quality indicators, defect minimization, care-quality improvements, and patient-safety enhancements. Improvement in this area runs through revision of generally accepted practices across healthcare. Behavior change can be driven through continuous, effective training, feedback, notification, financial incentives, administrative rules, or sanctions. Realistic performance principles and risk-adjusted results help laboratories improve both quality and performance reporting.